However dim their congressional prospects look this election year, Republicans are at least feeling pretty good about the state of play in Louisiana. The G.O.P. swept all but two statewide offices in last fall's elections, including the governors' office, where U.S. Rep. Bobby Jindal replaced one-term Democrat Kathleen Blanco. Now Republicans have their sights set on an even bigger prize: the Senate seat currently held by Democrat Mary Landrieu.